The present invention relates to a capsule endoscope, an endoscope system, a method for operating a capsule endoscope, and the like.
A capsule endoscope is small, and is normally controlled with respect to the frame rate in order to reduce the number of captured images so as to reduce power consumption, for example. The frame rate of the capsule endoscope is controlled corresponding to the speed at which the capsule endoscope moves through the digestive tract. The frame rate of the capsule endoscope is decreased when the motion speed is low, and is increased when the motion speed is high.
For example, JP-A-2006-223892 discloses a frame rate control method. According to the method disclosed in JP-A-2006-223892, a capsule main body that has been introduced into the body of a subject through swallowing captures images using a camera, and transmits the captured images to a reception device (extracorporeal device) that is situated outside the body of the subject. A processor device (extracorporeal device) that is situated outside the body of the subject detects the motion amount (analyzes the motion of the capsule main body) from the degree of similarity between the received captured images, determines an appropriate frame rate based on the motion amount, and transmits information about the frame rate to the capsule main body to control the frame rate of the camera provided to the capsule main body.
JP-A-2010-35746 discloses another frame rate control method. According to the method disclosed in JP-A-2010-35746, a capsule main body that has been introduced into the body of a subject through swallowing captures images using a camera, and transmits the captured images to a reception device (extracorporeal device) that is situated outside the body of the subject. A processor device (extracorporeal device) that is situated outside the body of the subject acquires information about the peristalsis of the digestive tract (organ) using a sound sensor, determines the degree of similarity between the received captured images, measures the motion of the capsule main body from the information about the peristalsis and the determination result for the degree of similarity, sets the frame rate to a normal frame rate or a special frame rate based on the measurement results, and transmits information about the frame rate to the capsule main body to control the frame rate of the camera provided to the capsule main body.